Wrenches make our life much easier, people can use different wrenches for different working environments according to their needs. There are all kinds of conventional wrenches such as hexagonal wrenches, open wrenches, mobile wrenches, and socket wrenches, etc.
Socket wrenches are divided into fixed socket wrenches and adjustable socket wrenches. The design and application of a socket wrench are described as follows:
1. A fixed socket wrench as disclosed in the R.O.C. Patent No. 450181 entitled “Contractible positioning structure of powerful wrench socket” comprises a wrench body, a rotary section disposed at an end of the wrench body, a rotary coupler with a rectangular cross section connected to the rotary section for connecting sockets of different sizes. When a force is applied to rotate the wrench body, the wrench rotates back and forth in order to save power. However, the wrench body of the prior art has a fixed length, which limits the application of a long-distance force when needed.
2. A contractible wrench as disclosed in the R.O.C. Patent No. 122740 entitled “Improved adjustable handle structure of adjustable socket wrench” comprises a socket wrench body in the shape of a rod and a handle in the shape of a pipe. The wrench body is disposed inside the handle and capable of moving along the axial direction of the handle for adjusting the length of the wrench as needed. However, the conventional adjustable socket wrench not only clamps the fingers easily when the length is adjusted, but is also easy to slip when a force is applied to the wrench.
In view of the shortcomings of the aforementioned prior art, a tool wrench according to this invention is disclosed.